1/*
2 * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
3 * Licensed under the GPL
4 */
5
6#include "linux/kernel.h"
7#include "linux/list.h"
8#include "linux/slab.h"
9#include "linux/signal.h"
10#include "linux/interrupt.h"
11#include "init.h"
12#include "sigio.h"
13#include "irq_user.h"
14#include "irq_kern.h"
15#include "os.h"
16
17/* Protected by sigio_lock() called from write_sigio_workaround */
18static int sigio_irq_fd = -1;
19
20static irqreturn_t sigio_interrupt(int irq, void *data)
21{
22	char c;
23
24	os_read_file(sigio_irq_fd, &c, sizeof(c));
25	reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ);
26	return IRQ_HANDLED;
27}
28
29int write_sigio_irq(int fd)
30{
31	int err;
32
33	err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt,
34			     IRQF_DISABLED|IRQF_SAMPLE_RANDOM, "write sigio",
35			     NULL);
36	if(err){
37		printk("write_sigio_irq : um_request_irq failed, err = %d\n",
38		       err);
39		return -1;
40	}
41	sigio_irq_fd = fd;
42	return 0;
43}
44
45/* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
46static DEFINE_SPINLOCK(sigio_spinlock);
47
48void sigio_lock(void)
49{
50	spin_lock(&sigio_spinlock);
51}
52
53void sigio_unlock(void)
54{
55	spin_unlock(&sigio_spinlock);
56}
57